1. Field of the Invention
This invention is in the field of therapeutic devices for enterally (e.g. by mouth) hydrating patients with cooled fluids.
2. Description of the Related Art
Ensuring that a patient is adequately hydrated is one of the most fundamental levels of medical care. Absent adequate hydration, blood pressure can fall dangerously low, blood may fail to adequately circulate, and organs may begin shutting down.
As a result, there has been a substantial amount of prior art interest in ensuring that patients are adequately hydrated. At present, the first line of hydration often begins with placing an IV line for direct parenteral administration of fluid directly into the patient's veins, it is often not ideal to keep this up for long. IV administration requires sterile fluids and IV lines, can expose the patient to some risk of infection, and other complications. If the patient is subsequently able to drink fluids without assistance, IV fluid administration will often be stopped and the patient directly “stepped down” to self enteral administration (e.g. by mouth). This self enteral administration can be as simple as providing the patient with a cup often a pitcher of fluid, along with instructions as to how much to drink.
Some patients, however, remain unable to drink fluids without assistance, often for some period of time. These “unable to drink” patients generally fall into two categories. One category may suffer from severe sickness that hampers the enteral fluid administration route, and/or be so incapacitated as to be unable to swallow (i.e. many intensive care patients). A second category may have an adequately functioning enteral system (i.e. able to swallow, stomach can handle fluids, intestine can absorb fluids and so on), yet be unable to use a cup without assistant. This can range from individuals with both upper arms in a cast, to other upper extremity injuries, arm amputations, partial or total paralysis, and the like.
At present patients who are at least able to sip and swallow and otherwise adequately handle fluids by mouth are often stepped down from IV administration, and their fluid needs are instead handled by assisted enteral administration. This assistance is often done by having a nurse or family member hold the cup up to the patient's lips, and allow them to sip and swallow. However this assisted enteral fluid administration route is quite time consuming, and whenever possible, the preferred option is to step the assisted enteral administration patient down to self enteral administration as soon as feasible.
Because of the high amounts of labor required for assisted enteral administration, other workers have suggested methods to automate or semi-automate the process.
For example, Deane in U.S. Pat. No. 2,756,740 proposed a drinking device for hospital patients that provided a push button valve to enable a patient to receive fluids from an overhead suspended container.
Similarly, Metz in U.S. Pat. No. 2,969,064 proposed a drinking tube device with a clamp-like mouthpiece with a unique internal structure that rotated and rocked to dispense fluid when activated by biting.
Similarly Edstrom in U.S. Pat. No. 5,484,405 proposed a drinking device for handicapped persons that had a semi-permanently positioned mouthpiece that was held into position by a stiffener rod, wire, or other material that was affixed to the tube that transmits fluids from the fluid reservoir to the device's mouthpiece.
More complex electronic devices were taught by Turner in U.S. Pat. No. 4,966,580. Here a nipple held on the patient's tongue has a sensor that, in response to the patient's sucking the nipple or pressing the nipple, sends an electronic signal to a peristaltic pump to pump fluids into the patient's mouth.
Despite these and other prior art proposals, none of these devices has apparently been successful enough to catch the attention of the medical community. Even recent review articles, such as “A guide to enteral access procedures and enteral nutrition” O'Keefe, s. J. D. Nat. Rev. Gastroenterol. Hepatol. 6, 207-215 (2009) show that clinician's primarily view enteral administration as either traditional utensils, more heroic interventions such as nasogastric feeding tubes, and not much else. Thus improved methods of enteral fluid administration that fall somewhere in-between a traditional cup and a nasogastric tube would be medically useful.
In applicant's previous disclosures, such as U.S. patent application Ser. No. 13/347,274 and U.S. provisional application 61/431,309, the complete contents of both are incorporated herein by reference, applicant taught a device and method for these purposes. Specifically applicant taught a device and method for enterally hydrating a patient, such as a paralyzed or limited upper body mobility patient with a functional gastrointestinal system who is nonetheless incapable or not fully capable of drinking unassisted. In these disclosures, applicant taught that fluids may be provided by a suspended flexible or semi-flexible container with graduation markings to allow for convenient estimation of fluid use, an upper open and closeable cap to allow the container to be refilled, and a lower fluid conducting tube that terminates in a mouthpiece, which contains a fluid valve formed from at least one slit in an elastic material (e.g. valve material). Patient mouth force on the valve material causes the slit to enlarge, thus enabling fluid to flow into the patient.
U.S. patent application Ser. No. 13/347,274 and 61/431,309 utilized the concept that although the previously discussed complex fluid valves from prior art medically related designs have generally proven not to be successful, more recently, the sporting equipment world has come up with a number of both simple, low cost, yet highly effective fluid valves to enable athletes to drink without using their hands or arms while running, cycling, hiking, and the like.
For example, Fawcett, In U.S. Pat. No. 5,085,349 disclosed a “resilient valve and dispensing system for bicyclists” that is both simple and robust. Further, Cascade Designs Inc., of South Seattle Wash. produces a platypus mouthpiece that is also simple and robust (see, for example, Getzewich “Bite Valve for Personal Hydration Devices and a Method for Making the Same”, US publication number 2002/0011583; and Lerner, “Dispensing Valve for a Flexible Liquid Container”, U.S. Pat. No. 5,730,336. Other sporting equipment organizations, such as Camelbak Products, LLC, Petaluma Calif. also produce simple and robust fluid valves which may potentially be useful for these purposes as well.
Thus U.S. patent application Ser. No. 13/347,274 and 61/431,309 were based, in part, on the insight that the way to move forward in the field of patient enteral hydration techniques was to develop a more modern patient self-administered enteral device based various state-of-the art methods in plastics and fluid valve technology.
The work of Ser. No. 13/347,274 and 61/431,309 was also based, in part, on the insight that what was needed is a new type of hydration device that configured somewhere between an IV bag on the one hand, and a sports/fitness like personal hydration system (e.g. CamelBak™, Platypus™ etc).